1. Field of Invention
The invention generally relates to an electronic device, and more particularly to a touch display apparatus and a touch mode switching method thereof.
2. Description of Related Art
With the rapid development of technology, most electronic devices, such as notebook computers, mobile phones or portable multimedia players, usually adopt touch panels as input interfaces. Based on different sensing types, a touch panel can be generally categorized into a resistance touch panel, a capacitive touch panel, an optical touch panel, an acoustic-wave touch panel and an electromagnetic touch panel. The capacitive touch panel is characterized by short response speed, favorable reliability, satisfactory durability, and so on. Therefore, the capacitive touch panel is widely used in the electronic products.
The capacitive touch panel is operated by approaching or touching the touch panels with a finger or a conductive material to change the capacitances of the touch panel. When variation of the capacitance values is detected, the location approached or touched by the finger or conductive material can be identified to further execute a predetermined operation corresponding to the foregoing approached or touched location.
When using the stylus pen to perform the touching, the touch mode of the capacitive touch panel has to be switched to improve the sensitivity of the capacitive touch panel in order to judge the touch position of the stylus pen accurately. However, because the touch sensing signal intensity of the stylus pen is similar to the noise of the capacitive touch panel, it is easy to erroneously judge the noise as the touch sensing signal of the stylus pen for the capacitive touch panel. The capacitive touch panel is then switched to the high sensitivity touch mode, which increases unnecessary power consumption.